Discussion Overview
The discussion revolves around whether an object's temperature can change in a vacuum when the vacuum container is placed in a hotter or colder environment, focusing on the mechanisms of heat transfer involved, particularly radiative heat transfer.
Discussion Character
- Exploratory
- Technical explanation
- Debate/contested
Main Points Raised
- One participant questions if an object at temperature T in a vacuum can change temperature by altering the environment around the vacuum container.
- Another participant asserts that an object inside a vacuum chamber will stabilize at the same temperature as the chamber walls, indicating that changing the wall temperature will affect the object through radiation heat transfer.
- A claim is made that conduction can occur between the container surfaces and the object, although this is contested based on the design of vacuum containers like Thermos bottles.
- It is noted that if an object is suspended in a vacuum chamber, conduction would be minimal due to lack of contact with the chamber walls.
- One participant suggests that the rate of heat transfer depends on the temperature difference between the object and the walls, implying a relationship that may be quick with a significant temperature difference.
- A later reply discusses the design of cryogenic dewars, highlighting that polished, silvered walls reflect infrared radiation to reduce radiative heat transfer, and questions the logarithmic nature of heat transfer, suggesting it follows a T^4 relationship instead.
Areas of Agreement / Disagreement
Participants express differing views on the mechanisms of heat transfer in a vacuum, particularly regarding the roles of conduction and radiation, and there is no consensus on the specifics of the heat transfer formula.
Contextual Notes
There are unresolved assumptions regarding the conditions under which heat transfer occurs, such as the degree of contact between the object and the chamber walls, and the specific mathematical relationships governing radiative heat transfer.